This invention relates generally to a pneumatic tire carcass and more particularly to a tire carcass having cut-resistant sidewalls.
Large earthmoving tires are used in severe operating conditions where the sidewalls of the carcass are susceptible to cuts by rocks or other sharp and penetrating objects. After the sidewalls are initially cut or punctured, the sidewall cuts continue to propagate due to the cyclic operating conditions. Particularly, a radially oriented cut in the sidewall tends to open up every time that the cut is rotationally oriented downwardly or in the footprint. As a consequence, the cut continues to grow in length and in depth to the point of failure. If the remainder of the tire has useful life remaining, this is an expensive loss.
Heretofore, thicker sidewalls have been provided to improve cut resistance. However, the thicker sidewalls do not significantly reduce the tension in the rubber or elastomeric material at the surface and hence do not appreciably improve cut resistance of the tires. Moreover, not only is this a relatively expensive proposition, but also the heavier tires generally run hotter so that their durability is adversely affected.